The invention relates generally to data storage systems, and in particular, to job scheduling for I/O tasks directed to devices in data storage systems.
In typical data storage systems, a storage controller serves as an interface between external host computers and the physical storage devices of the data storage system, and thus controls all back-end (or device-side) operations. The back-end operations can include services for read misses, as well as write destaging, read prefetching, RAID, data copy and other types of background operations. The scheduling of these types of operations has a major effect on the performance of the data storage system as a whole.